CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CONSOLIDATED BALANCE SHEETS
Fixed maturity investments, amortized cost (in dollars)	$ 2,375.4	$ 2,662.2
Equity securities, cost (in dollars)	115.4	38.1
Other investments, cost (in dollars)	$ 70.8	$ 143.1
Non-cumulative preferred shares ("Preferred Shares"), issued shares	6,000,000	6,000,000
Common Shares, shares issued	50,948,153	56,711,141
Treasury shares, shares	1,163,239	1,441,451